++1 on Rip's great system.
However, after I replicated his system, I simply used Dutch Stingerz instead of a simple prussik on the ridgeline for a more solid connection (in case of stormy weather) and for the same ease of adjustment.
As Dutch puts it: "Stingerz-same easy connection using 1.75 hollow braid line combined with a mini titanium carabiner so you can freely move your ridgeline."
Give it a try! It works really great.
Just my 2 cents.